Method for controlling the bending deformation of a turbomachine shaft at rest subjected to the residual heat of operation of the turbomachine

Abstract

A method for controlling the bending deformation of a turbomachine shaft at rest subjected to the residual heat of operation of the turbomachine, wherein the shaft is rotated at a rotation speed between 0.1 and 50 revolutions per minute depending on the bending deformation deflection of the shaft when the turbomachine is at rest.

The invention claimed is: 
     
       1. A turbomachine comprising a casing and a shaft that is movable in rotation with respect to the casing, a drive system configured to drive the shaft in rotation when the turbomachine is at rest, a sensor configured to measure a bending deformation deflection of the shaft when the turbomachine is at rest, and a control unit, the control unit being configured, when the turbomachine is at rest, to actuate the drive system when the deformation deflection of the shaft measured by the sensor is greater than a first predetermined value, and to stop rotating the shaft when both the deflection is less than or equal to a second predetermined value, the second predetermined value being less than the first predetermined value, and at the end of a second predetermined period counted from the time where the deflection becomes smaller than the second predetermined value. 
     
     
       2. A method for controlling the bending deformation of a turbomachine shaft at rest subjected to the residual heat of operation of the turbomachine, wherein the shaft is rotated at a rotation speed comprised between 0.1 and 50 revolutions per minute only when a bending deformation deflection of the shaft is greater than a first predetermined value, wherein rotating the shaft is stopped when both the deflection of the shaft is less than or equal to a second predetermined value, the second predetermined value being less than the first predetermined value, and at the end of a second predetermined period counted from the time where the deflection of the shaft becomes less than the second predetermined value. 
     
     
       3. The method according to  claim 2 , wherein the second predetermined value is 30% less than the first predetermined value. 
     
     
       4. The method according to  claim 2 , wherein the deflection of the shaft is measured, and the shaft is rotated depending on the result of the measurement. 
     
     
       5. The method according to  claim 2 , wherein the shaft is rotated depending on a predetermined predictive model. 
     
     
       6. A non-transitory computer readable medium storing a computer program including instructions for the execution of the method according to  claim 2 , when said computer program is executed on a computer.